| Autor: |
Calvo B, Torres-Vidal P, Delrio-Lorenzo A, Rodriguez C, Aulestia FJ, Rojo-Ruiz J, McVeigh BM, Moiseenkova-Bell V, Yule DI, Garcia-Sancho J, Patel S, Alonso MT |
| Jazyk: |
angličtina |
| Zdroj: |
BioRxiv : the preprint server for biology [bioRxiv] 2024 Jul 26. Date of Electronic Publication: 2024 Jul 26. |
| DOI: |
10.1101/2023.07.11.547422 |
| Abstrakt: |
Endo-lysosomes are considered acidic Ca 2+ stores but direct measurements of luminal Ca 2+ within them are limited. Here we report that the Ca 2+ -sensitive luminescent protein aequorin does not reconstitute with its cofactor at highly acidic pH but that a significant fraction of the probe is functional within a mildly acidic compartment when targeted to the endo-lysosomal system. We leveraged this probe (ELGA) to report Ca 2+ dynamics in this compartment. We show that Ca 2+ uptake is ATP-dependent and sensitive to blockers of endoplasmic reticulum Ca 2+ pumps. We find that the Ca 2+ mobilizing messenger IP 3 which typically targets the endoplasmic reticulum evokes robust luminal responses in wild type cells, but not in IP 3 receptor knock-out cells. Responses were comparable to those evoked by activation of the endo-lysosomal ion channel TRPML1. Stimulation with IP 3 -forming agonists also mobilized the store in intact cells. Super-resolution microscopy analysis confirmed the presence of IP 3 receptors within the endo-lysosomal system, both in live and fixed cells. Our data reveal a physiologically-relevant, IP 3 -sensitive store of Ca 2+ within the endo-lysosomal system. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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